A major winter storm is rapidly developing now that low pressure has moved to the leeward side of the Rocky Mountains in Colorado. Blizzard conditions and heavy snow will impacts millions from the mountains to parts of the Plains, Upper Midwest, Great Lakes, and Northeast. According to the National Weather Service, Winter Storm Warnings are currently in effect from New Mexico through Wisconsin, with a Blizzard Warning in place for a small portion of North Dakota. Meanwhile in the warm sector of this storm, severe storms and heavy rain will target the South and East Coast.
This evening, a widespread area of snow, some of which will be heavy, will be impacting much of the Dakotas and into Minnesota while pockets of mixed wintry precipitation affect parts of Nebraska. Then into the overnight hours of Wednesday, we’ll see snow overspread into northern Wisconsin and even the Upper Peninsula of Michigan. As the warm air lifts to the north and east, places like southern Minnesota will actually changeover from a heavy snow to rain. What will be interesting to watch is the area of rain that will span from Nebraska to New Mexico, because it will actually transition into a heavy snow, triggering that Winter Storm Warning.
Then on Thursday, a narrow but mighty band will traverse across a large section of the Plains, so from the eastern Dakotas through the Texas Panhandle there will be a round of heavy snow which should last for a few hours. As cold air tries to funnel in from the north while low pressure moves to the north and east across the Upper Midwest, the rain may transition back to snow across southwestern Minnesota and surrounding areas before the precipitation completely shuts off by Friday morning. Similar to Wednesday night, the warm front will continue to trek northeastward, so now the Upper Peninsula of Michigan should experience a changeover to rain, making for sloppy travel conditions following that snow.
Thursday night, the main event will have ended in the Midwest and Plains, but there may still be a lingering area of light to moderate snow across the region, which could last into Friday. Meanwhile in the Northeast, cold air at the surface will allow for a period of freezing rain and/or sleet or possibly even snow, especially central and Upstate New York in addition to northern New England and the Berkshire Mountains of Massachusetts. The best chance for snow will be in Maine, where several inches and up to half a foot is expected to accumulate.
That wintry weather will continue through midday Friday in Maine while rain affects the rest of the Northeast.
Another issue with this winter storm will be the gusty winds and blizzard conditions. The best risk for a blizzard will be in the eastern Dakotas and Minnesota. Keep in mind, blizzard criteria is when visibility is less than a quarter mile while winds consistently gust at speeds greater or equal than 35 mph, all while lasting for at least three consecutive hours. Elsewhere in the snow zone, most locations can expect wind gusts of 30-50+ mph, which may lead to scattered power outages.
The stormy side of this post-holiday cyclone will affect a large part of the US from the southern Plains through the East Coast between now and Friday. Even severe storms will be possible on both Wednesday and Thursday.
This evening into tonight, the severe weather risk will be in most of Texas. During the evening, severe storms will be hit or miss and scattered before a line of strong to severe thunderstorms forms overnight and tracks east across the state, likely containing gusty to damaging winds. Small hail cannot be ruled out but is not expected. There will also be the risk for tornadoes through tonight, especially in central Texas. That’s because the greatest wind shear will be located there.
Meanwhile to the north and east, rain will be the story. A widespread rain will impact the Plains and Midwest between now and tonight while numerous, frequent showers affect the Gulf Coast states. Some of this rain will be heavy, but we’re not too concerned about flooding. The only region that may experience minor, localized flooding will be in the southern Plains.
On Thursday, the rain and severe weather threat will shift to the east. This time the risk for severe thunderstorms will be focused on Louisiana and Mississippi but surrounding states should also stay alert for spotty, dangerous storms. Again, the main risk associated with the line(s) of storms that moves through is damaging winds, but a few brief, spin-up tornadoes are also expected.
Rain will remain a story on Thursday from the Great Lakes and Ohio River Valley down through the Gulf Coast. Most of the East Coast will remain dry until Thursday night, which is when that moisture will begin to work into the region. There may even be a few showers that sneak into the Mid-Atlantic during the day Thursday. Again, the best risk for flooding will be closest to the moisture source of this storm, which is the Gulf of Mexico, so the Gulf Coast states will need to be aware of this threat.
By Friday, all eyes will be on the East Coast as the low pressure continues to move east. A heavy line of rain associated with a funnel of deep moisture coming in from the south will lead to ponding and some flooding in the Northeast Megalopolis. This rain event shouldn’t be as significant as last Friday’s but there will still be heavy rain that may trigger flooding. Based on the current timing of this rain, the morning and midday time period should feature the worst of weather conditions before the cold front begins to clear the moisture offshore beginning Friday evening.
See our below map for an outline on what weather you can expect with this major, late-week storm system.